[SciPy-Dev] Levenberg-Marquardt Implementation

[josef.pktd at gmail.com]

On Tue, Jun 17, 2014 at 10:32 AM, Sturla Molden <sturla.molden at gmail.com> wrote:
> Sturla Molden <sturla.molden at gmail.com> wrote:
>> william ratcliff <william.ratcliff at gmail.com> wrote:
>>> This issue does seem to come up regularly.   There is a BSD licensed
>>> version:
>>> <a href="https://github.com/newville/lmfit-py">https://github.com/newville/lmfit-py</a>
>>>
>>> For mpfit.py, at one point, I got license permissions for scipy from the
>>> original authors, but no one wanted to include it.   Has that changed?  I
>>> haven't followed the issue since 2012.
>>
>> I just looked briefly at the code. It seems to use scipy.optimize.leastsq
>> for Levenberg-Marquardt, so what is the extra benefit?
>
> For the record: scipy.optimize.leastsq and scipy.optimize.curve_fit are
> Levenberg-Marquardt solvers.

curve_fit and lmfit are wrappers for Levenberg-Marquardt.

What scipy needs, among other things, are more pure optimizers.

lmfit allows fancier parameter definitions, imposes constraints
through reparameterization and produces more results statistics. The
optimizer that it uses is just Levenberg-Marquardt, although IIRC it
also wraps other optimizers.

Josef


>
> Sturla
>
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